alt Hacker NewsIt's probably a complexity and cost thing: heating the wheel just requires heating wires in the wheel connected to a switch. Cooling requires a some cooling medium getting pumped into the wheel and back out into a heat exchanger or vented outside. You need pipes of some sort inside the wheel and wheel hub.
You're way overthinking this. Making the steering wheel an AC vent is a Mercedes Benz patent. It's just hollow on the inside.
We also used to have crotch vents beneath the steering column! This was arguably the best idea since it could cool the entire driver area including the wheel.
This is artificial scarcity like the McRib.